China Great Wall is a collective name of the construction of the vast scale of the military engineering. It was built to resist the invasion of Saibei nomads Union in different periods of ancient China by kinds of different dynasties. It stretches thousands of kilometers from the east to the west, so it is also known as Wanli Great Wall. The existing relics of the wall are mainly built in the 14th century in Ming Dynasty, which is called Ming Great Wall. It extends in Jiayuguan in the west to Tiger Mountain in the east. This section of attraction runs across Beijing, Tianjin, Qinghai, Shandong, Inner Mongolia and other 15 provinces and autonomous regions. And there are a total of 43,721 Wall Heritage sites in China today. It has been the most significant single building since the existing of human civilization. And the time of its reparation also lasts the longest compared to other significant building in China.

In April 2009, China National Mapping Bureau and the National Heritage Board reports the latest full archaeological research, which shows that the Ming Great Wall has a length of 8,851.8 km, of which artificial wall has a length 6259.6 kilometers, fosse has a length of 359.7 km and natural insurance has a length of 2232.5 km. the average height of walls is 6 to 7 meters and the width is 4 to 5 meters.

On June 5, 2012, the State Administration of Cultural Heritage announced that, after nearly five years of investigation it found that the total length of China's ancient giant wall is of 21,196.18 kilometers. This is China's first scientific and systematic measurement of the total length of the ancient building.

The construction of the project began in the Spring and Autumn dynasty period, so it has two thousand years of history. And it reaches its largest size in Qin, Han and Ming Dynasties. When it comes to Tang Dynasty, the kind stopped building this wonderful works for it was peaceful at that time and there was no need to building the Wall for defense. The last largest reparation happened in Ming Dynasty. In this time, the kind of Ming Dynasty built this engineering projec in large scale, so it extended a lot in this period.

Visiting China Great Wall has become a fashion for domestic and foreign visitors. There are hundreds of thousands of travelers coming to Beijing to see the significance of this ancient great engineering project.

Source from: http://www.topchinatravel.com/china-guide/famous-landmarks-in-china.htm